Saturday, September 3, 2011

About Taubes, Guyanet, Science, AHS and Missing Rulers

From most recent and going back:

Guyanet answers Taubes:  http://wholehealthsource.blogspot.com/2011/09/response-to-gary-taubes-framing-debate.html

Taubes answers Guyanet conflict from AHS:  http://www.garytaubes.com/blog/

Guyanet describes the conflict at AHS:  The Carbohydrate Hypothesis of Obesity: a Critical...

I'm still trying to digest Guyanet's perspective, which is tough because it is not laid out in a book, but is also less lengthy than Taubes cryptic, 400+ page masterpiece Good Calories Bad Calories.  I found GCBC to be so profound, I read it four times with multiple additional forays into it to answer specific questions as they occurred to me.

I hope it won't take as long to digest Guyanet's description of the wretchedly titled "food palatability" hypothesis.  Here's a summary:
Carbohydrate consumption per se is not behind the obesity epidemic.  However, once overweight or obesity is established, carbohydrate restriction can aid fat loss in some people.  The mechanism by which this occurs is not totally clear, but it has nothing to do with removing the supposed suppressive effect of insulin on fat release from fat cells.  Carbohydrate restriction spontaneously reduces calorie intake (as does fat restriction), suggesting the possibility that it alters body fat homeostasis, but this alteration likely occurs in the brain, not in the fat tissue itself.  The brain is the primary homeostatic regulator of fat mass, just as it homeostatically regulates blood pressure, breathing rate, and body temperature.  This has been suspected since the early brain lesion studies of the 1940s (47) and even before, and the discovery of leptin in 1994 cemented leptin's role as the main player in body fat homeostasis.  In some cases, the setpoint around which the body defends these variables can be changed (e.g., hypertension, fever, and obesity).  Research is ongoing to understand how this process works.

A couple of points in the interim:
1.  They are not arguing about whether or not carb restriction is helpful for people that are over weight.
2.  They are not arguing about whether or not Taubes' message on the faulty science of fat and saturated fat is incorrect.
3.  In short, one thinks the key to treating obesity is by eating to avoid hormonal dis-regulation, aka metabolic derangement.  The other thinks it is about hormonal dis-regulation also - but a different hormone.  One focuses on insulin function, one on leptin.  I'm not at all sure they are not both correct, but can't tell yet.
4.  As Guyanet frames it:  I'd like to begin by emphasizing that carbohydrate restriction has helped many people lose body fat and improve their metabolic health.  Although it doesn't work for everyone, there is no doubt that carbohydrate restriction causes fat loss in many, perhaps even most obese people.  For a subset of people, the results can be very impressive.  I consider that to be a fact at this point, but that's not what I'll be discussing here.  

The good news is that there's a fight between two, smart researchers and they both agree on fat.  The bad news is that this is too much like a couple guys in rain coats yelling "mine's bigger!" but neither can afford a ruler (my thanks to Coach Glassman for the analogy!).  However, aside from ego, it matters not "who's is bigger".  This kerfuffle only starts to matter if it results in the advancement of our understanding of how to use diet to optimize health.

I hope it will come down to this - both will propose a research study design that will test the relevant hypothesis, and those studies will be funded.  From that or those defining studies, we may get useful information about how to help people that are obese get well faster, and we may find out how to help lean, well people stay well if they want to.  There are a number of good intervention studies that show carb restriction is effective.  Perhaps there's a Guyanetesque refinement that will make carb restriction more effective or less restrictive.

On the Guyanet post, many have weighed in to say the equivalent of "I don't mind if you have a way to refine what Taubes is saying, but his book saved my life, don't get too personal in your writing."  I have a similar gratitude to Taubes - his book made an structured understanding of the science of diet possible to a guy like me who would never have a chance to pursue such an understanding via academia - and in a way that serves my style of learning far better than simple reading and test taking.  GCBC was a literal answer to my prayers and I spent two satisfying years digging through it.

I take it as a given that Guyanet has also helped many people, and has a great voice on elements of the paleo model that is not found elsewhere in the blogosphere.

If they do it right, all of us curious onlookers will benefit from the debate, and hopefully they will both be handsomely rewarded for their contributions to our collective understanding.

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